In an operation environment where two or more wireless network devices (such as wireless access points or mesh nodes) are operating within the interference ranges of each other on the same radio frequency (RF) band, it is preferable for each of the wireless network devices to operate on the RF channel with the least interference from other wireless network devices in the vicinity, thereby improving the capacity and performance of the system.
To determine which RF channel has the least interference from other wireless network devices in the vicinity, a wireless network device audits the whole spectrum of the RF band by performing a spectrum scan. Once the RF channel with the least interference is determined, the wireless network device, under the control of an internal or an external controller, switches over to the preferred RF channel.
A wireless network device with only one radio unit temporarily suspends its activity with associated client devices in order to perform a spectrum scan. While wireless network devices with two or more radio units are becoming increasingly common, with these devices, it is still impossible to simultaneously provide connectivity to client devices with one radio unit and perform the spectrum scan with a second radio unit with conventional methods because signals transmitted by the radio unit providing user access are received by the radio unit attempting to perform the spectrum scan. The radio unit attempting to perform the spectrum scan with conventional methods cannot successfully receive and decode signals from other wireless network devices in the vicinity due to receiver compression caused by the strong signal components corresponding to signals transmitted by the radio unit providing connectivity to client devices in the received signals.